1. Field of the Invention
The invention relates to an application unit for a liquid or viscous product that can be used in particular in the field of cosmetics, paints or glues. In the field of cosmetics, the product may be a composition of nail varnish or a nail care composition, or a liquid lipstick.
2. Description of the Related Art
In general, an application unit for nail varnish comprises a varnish reservoir provided with an opening and an element for applying the varnish, such as a brush comprising a tuft of bristles fixed to a first end of a stem, the stem being secured at its other end in a cap serving as a gripping element intended to close the reservoir so that the tuft of bristles is immersed in this varnish when the application unit is closed.
To ensure a proper closure of the unit, the reservoir has a neck provided with a first thread that cooperates with a second thread provided in the cap. The neck is generally thick and flat, and fitted with a sealing ring. The stem is held in position in the cap by means of a support such as a sealing disk. This sealing disk is in contact with the sealing ring of the neck when the application unit is closed.
To apply the varnish to the nail, the user removes the brush, impregnated with the product, from the reservoir. Generally, the brush has an excess of the product. It is therefore necessary to eliminate this excess and, for this purpose, the user removes the excess by wiping the brush on the free end of the neck of the reservoir. Since the end of the neck is flat and thick, some of the product will remain on the neck and flow along its outer side and thus foul its thread. When the user again screws the cap down to close the reservoir, the product expands over the neck and into the thread. After the product on the cap-neck assembly has dried, it forms an accretion so that in subsequent use it is difficult or even impossible to unscrew the cap from the reservoir. Moreover, the product on the neck prevents proper sealing of the application unit because the sealing disk is no longer in leakproof contact with the sealing ring of the neck. Also, because of the bearing of the disk on the neck, it is no longer possible to take up the play between the neck and the bearing surface after the first use; this reduces the sealing effect still further.
It has been proposed, in GB-A-2 198 423, to dispose within the neck tongues which form a collar for wiping the brush. In FR-A-1530702 it has been proposed to arrange in the neck an annular channel provided with a central duct into which the brush may be inserted, the brush being wiped on the free end of the duct. However, these wiping devices are disposed in the neck and are bulky, however the currently used units for applying nail varnish the neck have an opening of a small diameter which cannot accommodate these wiping devices. While would be possible to increase the diameter of the neck, this would involve a modification of the form of the varnish bottles, making it necessary to also adapt the accessories such as the cap to the new dimensions of the neck.
U.S. Pat. No. 2,815,146 describes a pot intended to contain a liquid such as a paint, there being disposed in the opening of the pot a wiper element in the form of an annular ring which has a portion capable of emerging from the opening by resilience when the lid of the pot is lifted. Thus an application element such as a brush can be wiped on the ring, and fouling of the edge defining the opening of the pot is avoided. But the pot according to this patent is not designed to form a unit ready for use and does not include the closing element associated with an application element.
DE-A-15 57 355 describes a wiper device for bottles of nail varnish. In one embodiment, a wiper tube is elastically suspended in the neck of the bottle, the free end of the tube emerging from the neck in the open position. In the closed position, the neck pushes the tube into the inside of the neck by axial translation. The device has the drawback that, after extracting the brush, the user must again pass it into a position on the free end of the tube which is inclined relative to the axis of the tube. Easy wiping of the brush or of the stem of the brush cannot be ensured by this device. Indeed, to dry the brush it is necessary either to perform a movement distinct from the movement causing the withdrawal of the brush from the bottle, or to substantially modify the extracting movement so as to wipe the brush against the edge of the wiping means at the end of the travel.